AIMTo analyze and compare the constituents of the volatile oil of Pogostemon cablin collected from different regions of cultivation and harvesting times in order to evaluate the quality of Shipai Huoxiang and to expound the chemical intension of Pogostemon cablin.

METHODSThe combination of GC and MS.

RESULTSThe volatile oil compositions of Herba Pogostemonis collected from various of cultivation regions and harvesting times are obviously different. Based on the chemical differences of the volatile oil compositions, Pogostemon cablin is divided into two chemotypes, Pogostone-type and Patchouliol-type. The former was cultivated in Guangzhou and Gaoyao regions, locally named as "Shipai Huoxiang"; the latter was locally named as "Hainan Huoxiang", cultivated in Wuchuan, Suixi and Leizhou regions of Guangdong Province and Wanning region of Hainan Province. The Pogostone-type contains rich oxygenated components, especially pogostone in the volatile oil compositions and poor non-oxygenated composition with patchouliol. The above chemical data may be used as evaluation standard for the authentic Shipai Huoxiang. The Patchouliol-type contains similar quantities of oxygenated and non-oxygenated composition, especially rich patchouliol with poor pogostone in oxygenated compositions, rich delta-guaiene and alpha-guaiene in non-oxygenation compositions. The contents of volatile oil and their constituents were varied due to different harvesting time. The yields of pogostone and volatile oil of Shipai Huoxiang was higher in July. The quality of the samples collected in this month was better.

CONCLUSIONAccording to the volatile oil compositions, there are two chemotypes (Pogostone-type and Patchouliol-type) in Pogostemon cablin plant. These two chemotypes correspond to the genotypes of plastid matK gene and nuclear 18s rRNA gene by cluster analysis.